Preheat oven to 350° F. In a baking pan toast pecans in one layer in middle of oven until golden, about 10 minutes, and cool. In a food processor finely grind pecans, wafers, and graham crackers. Add brown sugar, butter, and salt and pulse until combined well. Transfer mixture to a 9 1/2-inch springform pan and press evenly onto bottom and 1 1/2 inches upside.

In a bowl with an electric mixer beat cream cheese until fluffy and add eggs, 1 at a time, beating at low speed until just combined. Beat in bourbon, vanilla, and brown sugar until just combined. Pour filling into crust and put springform pan in a baking pan. Bake cake in middle of oven for 35 minutes. Leaving oven on, transfer cake in springform pan to a rack and let stand 5 minutes. (Center of cake will set as it cools.)

In a bowl stir together sour cream, brown sugar, and vanilla.

Drop spoonfuls of topping around edge of cake and spread gently over center, smoothing evenly. Bake cake in baking pan in middle of oven 10 minutes and cool completely in springform pan on rack. Chill cake, covered, at least 8 hours and up to 4 days.

Run a thin knife around inside edge of pan and remove side of pan. Transfer cake to a serving plate and let stand at room temperature 30 minutes.

Serve cake with bourbon butterscotch recipe on this site. http://mrdistilling.com/recipes/recipes/view/bourbon-butterscotch